Thanks to their exquisite specificity and sensitivity, monoclonal antibodies (Mab) are the most important research tool for detection, localization and quantification of cellular proteins and widely used for diagnosis and treatment of various human diseases. Conventional hybridoma approach for generating monoclonal antibodies is time-consuming, labor intensive and multistep process that requires immortalization of splenocytes by fusion to a myeloma cell line partner. To simplify the generation of antibodies and to increase the productivity, a novel hybridoma-free multiplex approach for accelerating antibody discovery is proposed. The objective will be achieved by multiple antigen immunization into transgenic H-2Kb-tsA58 mice harboring a mutant temperature-sensitive simian virus 40 large tumor antigen. Antibody-producing B cells stained with fluorescence-labeled antigens will be isolated by fluorescence activation cell sorting (FACS). Sorted antigen-specific splenocytes will be conditionally immortalized by culturing at permissive temperatures. In Phase I, the proposed approach will be validated by developing highly specific monoclonal antibodies to 10 cancer-related targets. In Phase II, the platform will be used to develop mouse monoclonal antibodies to at least 100 protein targets that are involved in cancer. Compared with traditional approach, the time required for Mab generation using this approach is expected to reduce at least in half, while ten-fold or more increasing antibody generation productivity with significant improvement of target-specificity due the selection criteria used during FACS.